1. Field of the Invention
The present invention pertains generally to clamping means and, more particularly, to a means for connecting, clamping or securing a wire, conduit, or the like to a vertical surface. More specifically, the invention relates to a single connector which is particularly adapted to connect a static/power grid ground conductor to various types of floor support pedestals in a computer installation system.
A typical computer installation involves locating the computer and power distribution interconnections beneath a raised floor in the computer room. The raised floor is constructed above the true floor of the structure, being supported above the true floor by means of vertical floor support pedestals. The latter types of floor support pedestals which are conventionally utilized are characterized by a vertical support post of either round or square cross-sectional configuration and being fabricated of steel and aluminum.
In order to insure the safety of computer personnel, it is essential that the computer equipment, as well as the electrical power distribution means from which it derives power, be properly grounded. The computer equipment and related enclosures must be connected to a reference grounding system to protect against high frequency noise. The power distribution system must be grounded in accordance with generally recognized safety standards, and should minimize noise pickup which might affect computer operation. The equipment grounding systems and the 60 Hz power distribution grounding network, which in effect comprise two separate grounding systems, must be bonded together for safety considerations to assure that no difference in potential exists exposed metal components.
The interconnection for the equipment and power distribution grounding systems are typically arranged beneath the raised floor of the computer room, with the floor support pedestals being utilized to establish a grounded grid that attenuates high-frequency noise. Proper attainment of the grid requires that the ground conductor be effectively secured to the raised floor support posts. Because each of the various system components in the overall data processing installation is associated with specialized contractors, i.e. computer manufacturer, electrical consultant/contractor, flooring contractor, the need exists for a ground connector which is able to be properly and easily installed on a floor support pedestal by a variety of contractors who might have access to the data processing installation, which is capable of accepting all types of existing floor support posts, which can be UL and CSA approved, and which effectively establishes a safe ground system. Moreover, the need exists for a single ground connector which is capable of coupling plural conductors to a vertical support post to establish a signal reference grid.
The subject invention addresses and satisfies the foregoing need for a ground connector by providing a connector which is particularly adapted for utilization in a computer grid ground system so as to reduce high frequency noise which might garble the computer language, to ground the power distribution system to minimize noise pickup from the associated electrical system, and to ground capacitance charge, such as static electricity, that can be present on flooring, carpeting, people and the like. The ground connector of the present invention achieves the preceding objectives by providing a ground connector adapted to be easily assembled to the vertical support post of a raised floor pedestal with only a few relatively simple components. The ground connector is uniquely designed to fasten one or plural ground conductors to a raised floor support post in order to create a computer grid ground system which is capable of performing the dual function of grounding static charges and electrical 60 Hz fault currents. Moreover, the ground connector of the invention possesses a novel design, enabling it to be mounted on all types of conventional support posts employed by the flooring industry. The latter types of vertical support posts include a square steel tube and a round steel or aluminum tube. The ground connector is adapted to secure the conductor to a flat side of the square tube or, alternatively, to a corner of the square tube formed by the convergence of two flat sides. In the case of a round tube, the ground connector is adapted to secure the conductor to a peripheral surface of the tube. The ground connector thus obtains direct low resistance contact between the conductor and the support post.
Additional salient attributes of the ground connector reside in its ability to accommodate a range of conductor and post sizes, and its adaptability to UL and CSA approval. The primary connector components are fabricated of tin plated bronze, thereby rendering the connector resistant to the potential corrosion which may result from cleaning fluids and liquid spills on the raised floor dripping thereunder onto the ground connector. As previously noted, the ground connector is simple to assemble, the respective components being secured together upon the support post by means of a nut which accepts a conventional nut driver, ratchet wrench or the like. The ease of assembly and relative simplicity of the ground connector allows it to be fastened to the floor support pedestal without the grounding conductor, thereby enabling floor installation trades to prefit the connector prior to installation of the grounding system by the appropriate specialists. By providing an effective, and virtually fail-safe connector, the subject invention eliminates the possibility that improper or makeshift devices will be installed on the floor supports to the detriment of safety and computer operating efficiencies.
2. Background of the Invention
It is known in the prior art to provide means for supporting a horizontal ground wire with respect to a vertical surface. U.S. Pat. No. 2,234,022, for example, shows a vertical fuse tube 1 having mounted thereon a clamping member which holds a wire by means of a pair of jaws. The clamping member secures the wire horizontally in relation to the post.
U.S. Pat. No. 4,189,198 discloses a coupling device for holding a ground wire. The coupling device, in turn, is attached to the vertical surface of a conduit coupling collar.
Similarly, U.S. Pat. No. 4,457,577 teaches a grounding clamp for coupling a cable tray to a horizontal grounding conductor. The grounding conductor is received in an upturned portion of the clamp. A second upturned portion of the clamp engages and is secured to the lip of the cable tray.
It is also generally known in the prior art to provide ground clamps for coupling a grounding cable and an electrical conduit. An example of such a device is shown in U.S. Pat. No. 3,985,411, wherein a clamp comprising complementary hinged clamp members embraces a conduit and a ground cable. U.S. Pat. No. 3,892,455 shows a similar ground clamp formed of a body portion and a cap portion.
U.S. Pat. No. 2,077,613 is directed to a ground fitting characterized by two parts which, when bolted together, receive a grounding pipe. One of the latter parts of the fitting is secured to a clamping piece which secures a grounding wire.
It can be seen from the prior art that the need exists for a ground clamp for computer installations which effectively establishes ground connections in a sub-floor grid, attenuates high frequency noise interference, grounds the power distribution system, grounds capacitance charge, and which is uncomplicated and easy to manufacture, corrosive-resistant, convenient to assemble, and adaptable to UL and CSA specifications.